package 剑指offer;

public class _25合并两个排序的链表 {
    public class ListNode {
     int val;
     ListNode next;
     ListNode(int x) { val = x; }
 }
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if (l1 == null){
            return l2;
        }
        if (l2 == null){
            return l1;
        }

        ListNode head = null;
        if(l1.val < l2.val){
            head = l1;
            l1 = l1.next;
        }else {
            head = l2;
            l2 = l2.next;
        }
        head.next = mergeTwoLists(l1, l2);
        return head;
    }
}
